CN110578571B - Hydraulic engine brake system - Google Patents
Hydraulic engine brake system Download PDFInfo
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- CN110578571B CN110578571B CN201910939444.4A CN201910939444A CN110578571B CN 110578571 B CN110578571 B CN 110578571B CN 201910939444 A CN201910939444 A CN 201910939444A CN 110578571 B CN110578571 B CN 110578571B
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- 238000007789 sealing Methods 0.000 claims abstract description 50
- 230000002093 peripheral effect Effects 0.000 claims description 6
- 230000009286 beneficial effect Effects 0.000 claims description 5
- 238000005259 measurement Methods 0.000 abstract description 10
- 230000033001 locomotion Effects 0.000 abstract description 9
- 230000004044 response Effects 0.000 abstract description 6
- 239000003921 oil Substances 0.000 description 139
- 230000009471 action Effects 0.000 description 13
- 230000000694 effects Effects 0.000 description 12
- 239000010720 hydraulic oil Substances 0.000 description 10
- 239000010705 motor oil Substances 0.000 description 10
- 230000007246 mechanism Effects 0.000 description 9
- 238000000034 method Methods 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- 239000012535 impurity Substances 0.000 description 6
- 230000035945 sensitivity Effects 0.000 description 4
- 238000005299 abrasion Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 230000004913 activation Effects 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/20—Adjusting or compensating clearance
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/46—Component parts, details, or accessories, not provided for in preceding subgroups
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/46—Component parts, details, or accessories, not provided for in preceding subgroups
- F01L1/462—Valve return spring arrangements
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
- F01L13/06—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for braking
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Braking Arrangements (AREA)
Abstract
The invention discloses a hydraulic engine braking system, which comprises a support frame, wherein a braking control device and a braking piston device are arranged on the support frame, the braking control device comprises a sealing piston which is slidably arranged in the support frame, two sides of the sealing piston in the support frame are respectively communicated with a one-way valve assembly and a pressure limiting valve assembly, a braking starting oil duct, a braking oil filling oil duct and a releasing pressure relief oil duct are arranged on the support frame, and the sealing piston is communicated with and cut off the releasing pressure relief oil duct in a reciprocating mode in the support frame; the brake piston device comprises a brake piston vertically and slidably arranged in the support frame, the bottom end of the brake piston extends out of the support frame to be in contact with the brake pin, and a brake cavity communicated with a brake oil charge channel and a release pressure relief channel is formed in the top of the brake piston; the invention has the advantages of stable oil charge, high response speed, stable and reliable braking stroke, convenient manual direct measurement, reduced motion friction and the like.
Description
Technical Field
The invention belongs to the technical field of engines, and particularly relates to a hydraulic engine braking system.
Background
The total mass of the modern automobile is larger and larger, the speed of the automobile is higher and higher, and the rolling resistance, wind resistance and internal friction loss of the automobile are smaller and smaller, which means that the self deceleration capacity of the automobile is reduced; meanwhile, due to the increase of the total mass of the vehicle, a service brake system (commonly called foot brake) of the vehicle cannot meet the braking requirement under the condition of high speed and heavy load. The brake is frequently stepped on for a long time, which causes the temperature of the brake pad to rise, the braking effect is reduced, even the braking is out of order, and the safety of people and vehicles is endangered!
In order to ensure the safety performance of the vehicle, a retarder or other auxiliary braking devices are required to be added, and the retarder is added to shunt the load of the wheel brakes so that the temperature of the wheel friction brakes is controlled within a safety range. The service brake system has the function of realizing the parking in an emergency, and can absorb large power in a short time, but the absorbed power can be greatly reduced along with the increase of the brake duration, so that the service brake system can not meet the requirement of the emergency parking of the automobile on a downhill slope. The retarder mainly has the function of reducing or maintaining the speed of a vehicle descending a long and large slope within a certain speed range, and is not a system for stopping the vehicle, but can be normally used on a flat road to reduce the speed of the vehicle. Although the power absorbed in a short time is smaller than that of service braking, the power absorbed by the brake pad can be basically kept unchanged for a long time, and especially in the whole downhill process, the characteristic can meet different continuous braking requirements when the vehicle continuously descends, the retarder can meet the requirements, the service frequency of foot braking can be effectively reduced, and the temperature of a friction plate is prevented from being increased, the braking effect is reduced and even the braking is failed due to long-time use of the brake pad.
Retarder has become a standard configuration for commercial vehicles in developed countries almost like engines and gearboxes.
National standard GB7258-2012 technical regulations for automobile operation safety is implemented in China on 9 and 1 of 2012; the national quality supervision office and national standard Committee of China in the 9 th month 29 th 2017 jointly issues and requires that GB7258-2017 'technical Act on motor vehicle operation safety' be executed 1 st month 1 st 2018, and an auxiliary brake is definitely specified in 7.5: passenger car with length greater than 9m (for special school bus, the length is greater than 8 m), truck with total mass greater than or equal to 12000kg, special operation vehicle, and dangerous goods transportation truck with total mass greater than 3500kg should be equipped with retarder or other auxiliary braking device. The performance of the auxiliary braking device of the passenger car with the length of more than 9m and no passenger standing area, the dangerous goods transportation truck with the total mass of more than 3500kg and the semi-trailer traction car equipment is that the car passes the type II or type IIA test specified in GB 12676.
Currently, a retarder of a commercial vehicle mainly comprises an eddy current retarder, a hydraulic retarder and an engine retarder. Engine retarders can be classified into engine brakes and exhaust brakes, with engine brakes being classified into compression-release brakes and bleeder brakes depending on the braking implementation.
When the engine brake is opened, the engine ECU sends an instruction for stopping oil injection to the oil injector, the engine brake piston stretches out to open the brake exhaust valve, gas in the engine cylinder escapes through the opened brake exhaust valve, and no fuel is combusted in the engine cylinder, so that the engine does not provide traction force for the vehicle. The vehicle continuously rotates by driving the engine crankshaft through the driving wheel and the transmission belt, kinetic energy input by the vehicle to the engine is gradually consumed in the aspects of pumping loss (power loss caused by gas throttling in the intake and exhaust strokes) of the engine, mechanical friction loss of the vehicle, irreversible loss generated in the compression and expansion processes, power loss for driving engine accessories (an oil pump, a water pump, an air compressor, a steering pump, a fan and the like) and the like, the engine which is originally a vehicle power source is changed into the air compressor which consumes kinetic energy of the vehicle and plays a role of slowing down the vehicle speed, or the engine does negative work at the moment that the engine blocks the rotation of the crankshaft is changed into braking moment, and the braking moment is transmitted to the driving wheel through the transmission system.
The brake oil way control device belongs to the core technology of the engine brake, and mainly has the functions of when braking: by controlling the oil way, sealed high-pressure oil is formed in the brake control oil way, the brake piston stretches out a brake stroke under the action of external force (brake oil pressure, a mechanical device, air pressure or an electromagnetic mechanism), and the brake exhaust valve is opened under the drive of the top high-brake oil pressure or the cam brake stroke, so that engine braking is realized.
At present, a brake oil path control device mainly comprises an integrated hydraulic control device and a split hydraulic control device. The integrated hydraulic control device is characterized in that a hydraulic system controlled by an electromagnetic valve is added on an engine to form a hydraulic chain to control the opening of an exhaust valve, so that the engine braking function is realized, and the structure has the defects that pressure bearing oil is always in a closed cavity in a long-term braking process, and the continuous braking effect of a brake can be influenced due to high-pressure leakage; the oil charge response speed is generally every time the brake is turned on. The split type hydraulic control device mainly divides an oil inlet channel into two paths, the oil inlet pressure is lower, the oil filling efficiency is low, the oil channel is too long, the whole oil channel is full, the oil filling response speed is poor, the oil filling time is long, and the brake sensitivity is poor.
The braking piston belongs to the core component of the engine brake, and mainly has the function of stretching a braking stroke under the action of external force (braking oil pressure, a mechanical device, air pressure or an electromagnetic mechanism) during braking, and opening a braking exhaust valve under the driving of high top braking oil pressure or cam braking stroke so as to realize engine braking.
In the prior art, publication number CN102414403a discloses a special rocker-arm engine brake, in which a hydraulic brake piston is designed, the brake piston comprises a valve body sliding in a rocker-arm mechanism, the top end of the valve body is arranged outside the valve body and is connected with an adjusting bolt on the rocker-arm mechanism, when the valve body is filled with hydraulic oil, the valve body is pushed to move downwards under the action of oil pressure under the action of a return spring, so that the braking process is realized. But this brake has the following problems: (1) When the maximum braking travel S of the valve body needs to be measured, the action of the spring force of the return spring needs to be overcome, so that the boss of the adjusting bolt in the valve body can be measured after being contacted with the bottom surface of the clamp spring seat, the measurement is inconvenient, and especially when the return spring is blocked, the error of a measurement result can be caused, and the braking performance is further influenced; (2) In the sliding process of the valve body in the rocker arm mechanism, motion friction can be generated between the valve body and the rocker arm mechanism, particularly when impurities exist between the valve body and the rocker arm mechanism, abrasion can be generated on the motion surface between the brake piston and the arm mechanism, part damage can be caused, and the brake piston is blocked when serious, so that the braking effect is influenced; (3) The return spring is located the valve body, and during braking, hydraulic oil enters into the valve body, and after braking is finished, hydraulic oil is discharged, but still has a part of hydraulic oil to remain in the valve body all the time, contacts with the return spring, when impurity exists, can influence the effect performance of return spring for return spring reset effect variation, and then influence braking effect.
Disclosure of Invention
The invention aims to solve the technical problem of providing a hydraulic engine braking system which has the advantages of stable oil filling, high response speed, stable and reliable braking stroke, convenience for manual direct measurement and capability of reducing motion friction.
In order to solve the technical problems, the technical scheme of the invention is as follows: the hydraulic engine braking system comprises a supporting frame, wherein a braking control device and a braking piston device are arranged on the supporting frame, the braking control device comprises a sealing piston arranged in the supporting frame, a one-way valve assembly and a pressure limiting valve assembly are respectively communicated with two sides of the sealing piston in the supporting frame, a sealing piston resetting device is arranged between the sealing piston and the pressure limiting valve assembly, a braking starting oil duct is communicated between the one-way valve assembly and the sealing piston, a braking oil filling oil duct is communicated between the one-way valve assembly and the braking piston device, a releasing pressure relief oil duct is communicated between the braking piston device and the pressure limiting valve assembly, and the sealing piston is communicated with and cuts off the releasing pressure relief oil duct in a reciprocating mode in the supporting frame;
the brake piston device comprises a brake piston vertically and slidably installed in the support frame, the bottom end of the brake piston extends out of the support frame to be in contact with the brake pin, a brake cavity communicated with the brake oil charge oil duct and the release pressure relief oil duct is formed in the top of the brake piston, and a brake piston reset device is arranged between the lower portion of the brake piston and the support frame.
As an optimized technical scheme, two sides of the sealing piston are respectively provided with a piston starting cavity and a piston oil storage cavity, the piston starting cavity is communicated with the one-way valve assembly, and the piston oil storage cavity is communicated with the pressure limiting valve assembly; the brake starting oil duct is communicated with the check valve assembly and the sealing piston through the piston starting cavity, the release pressure relief oil duct is communicated between the brake cavity and the piston oil storage cavity, and the sealing piston is communicated in the piston starting cavity in a reciprocating mode and cuts off the release pressure relief oil duct.
As the preferable technical scheme, the check valve assembly comprises a check ball valve which is used for connecting and disconnecting the piston starting cavity and the brake oil charge oil duct, a check valve return spring is arranged at the top end of the check ball valve, and the check valve return spring is connected to the supporting frame through a check valve plug.
As the preferable technical scheme, the pressure limiting valve assembly comprises a pressure limiting valve body fixedly arranged on the supporting frame, a pressure limiting ball valve used for pressure relief and pressure maintaining is arranged on the pressure limiting valve body, a pressure limiting return spring used for controlling the pressure limiting ball valve to open and close is arranged at the bottom end of the pressure limiting ball valve, and a pressure relief hole is formed in the pressure limiting valve body.
As a preferred technical solution, the sealing piston return device comprises a sealing piston return spring connected between the sealing piston and the pressure limiting valve assembly.
As a preferable technical scheme, an adjusting bolt is arranged at the top end of the supporting frame in a threaded manner, and the bottom end of the adjusting bolt is arranged in the brake cavity; and an antifriction device is arranged on the sliding peripheral surface of the brake piston matched with the support frame.
As a preferred embodiment, the friction reducing means includes a plurality of annular grooves provided on a sliding outer peripheral surface of the brake piston.
As an optimized technical scheme, a piston sliding part which is in sliding fit with the supporting frame is arranged at the upper part of the brake piston, a piston limiting cover which surrounds the brake cavity is arranged at the top end of the piston sliding part, a piston oil inlet channel which communicates the brake cavity with the brake oil filling channel is arranged on the piston limiting cover, and a piston rod which extends out of the supporting frame is arranged at the lower end of the brake piston.
As an optimized technical scheme, the brake piston resetting device comprises a return spring baffle plate arranged at the bottom of the supporting frame, a brake return spring for driving the brake piston to reset is arranged between the return spring baffle plate and the brake piston, the brake return spring is sleeved outside the piston rod, and two ends of the brake return spring are respectively propped against the return spring baffle plate and the piston sliding part.
As an optimized technical scheme, the upper part of the adjusting bolt is fixed on the supporting frame through a locking nut, a bolt adjusting groove which is beneficial to screwing in and screwing out is formed in the top end of the adjusting bolt, a limiting boss which is arranged in the brake cavity is formed in the bottom end of the adjusting bolt, and the outer diameter of the limiting boss is smaller than the inner diameter of the brake cavity; the top end of the piston limiting cover is provided with a limiting hole which limits the limiting boss in the brake cavity, and the limiting hole is a round hole or a long hole.
Due to the adoption of the technical scheme, the hydraulic engine braking system comprises a supporting frame, wherein a braking control device and a braking piston device are arranged on the supporting frame, the braking control device comprises a sealing piston arranged in the supporting frame, a one-way valve assembly and a pressure limiting valve assembly are respectively communicated with two sides of the sealing piston in the supporting frame, a sealing piston reset device is arranged between the sealing piston and the pressure limiting valve assembly, a braking starting oil duct is communicated between the one-way valve assembly and the sealing piston, a braking oil filling oil duct is communicated between the one-way valve assembly and the braking piston device, a releasing pressure relief oil duct is communicated between the braking piston device and the pressure limiting valve assembly, and the sealing piston is communicated with and cuts off the releasing pressure relief oil duct in the supporting frame in a reciprocating mode.
The brake piston device comprises a brake piston vertically and slidably arranged in the support frame, the bottom end of the brake piston extends out of the support frame to be in contact with a brake pin, a brake cavity communicated with the brake oil charge oil duct and the release pressure relief oil duct is formed in the top of the brake piston, and a brake piston resetting device is arranged between the lower part of the brake piston and the support frame; the beneficial effects of the invention are as follows:
(1) According to the invention, the pressure of the brake oil during release can be controlled by adjusting the oil release pressure of the pressure limiting valve assembly, so that the brake oil is prevented from being completely released to cause overlong oil filling time during next braking; the brake oil is stored under the action of the pressure limiting valve assembly, so that the brake oil way can be assisted to be filled more rapidly in the next braking, and the brake oil way has the advantages of stable oil filling, high response speed, high brake sensitivity and the like;
(2) The gap between the brake piston and the brake pin, namely the brake valve gap, is adjusted by rotating the adjusting bolt so as to meet different use requirements;
(3) The maximum gap between the lower bottom surface of the piston limit cover and the upper top surface of the limit boss is the maximum braking stroke of the invention, and the braking stroke of the invention is stable and reliable, is convenient for manual direct measurement, reduces the measurement difficulty and improves the measurement efficiency;
(4) The annular groove on the outer peripheral surface of the brake piston has the functions of storing oil and containing impurities carried in engine oil, so that the movement abrasion between the brake piston and the supporting frame is reduced, the service life of the brake piston is prolonged, and the brake accuracy is improved;
(5) The brake return spring is sleeved at the outer end of the piston rod, the brake return spring cannot be contacted when hydraulic oil works, the working environment where the brake return spring is located is good, the service life of the brake return spring can be effectively guaranteed, and compared with the prior art, the brake return spring has a better reset effect and a better braking effect.
Drawings
The following drawings are only for purposes of illustration and explanation of the present invention and are not intended to limit the scope of the invention.
Wherein:
FIG. 1 is a schematic diagram of an embodiment of the present invention;
FIG. 2 is a schematic view showing a structure of a brake control apparatus according to an embodiment of the present invention in a non-braking state;
FIG. 3 is a schematic view of a brake piston assembly according to an embodiment of the present invention in a non-braking state;
FIG. 4 is an enlarged view of the structure of the brake piston assembly in the non-braking state according to the embodiment of the present invention;
FIG. 5 is a schematic view of a brake control apparatus according to an embodiment of the present invention;
FIG. 6 is a schematic view of the brake piston assembly of the present invention in a braking configuration;
FIG. 7 is an enlarged view of the structure of the brake piston assembly according to the embodiment of the present invention when braking;
in the figure: 1-a support frame; 2-a brake control device; 21-sealing the piston; 22-a one-way valve assembly; 221-one-way ball valve; 222-a check valve return spring; 223-blocking by a one-way valve; 23-a pressure limiting valve assembly; 231-a pressure limiting valve body; 232-a pressure limiting ball valve; 233-a pressure limiting return spring; 234-pressure relief vent; 24-a brake actuation oil passage; 25-a brake oil charge passage; 26-releasing the pressure relief oil passage; 27-a piston activation chamber; 28-a piston oil storage chamber; 29-a seal piston return spring; 3-a brake piston device; 31-a brake piston; 311-piston slide; 312-piston limit covers; 313-piston oil feed passage; 314-a piston rod; 32-a brake cavity; 33-brake piston resetting means; 331-return spring baffle; 332-braking a return spring; 34-adjusting bolts; 341-a lock nut; 342-bolt adjustment slots; 343-limit boss; 344-a limiting hole; 35-an annular groove; 4-a brake pin; 5-exhaust valve.
Detailed Description
The invention is further illustrated in the following, in conjunction with the accompanying drawings and examples. In the following detailed description, certain exemplary embodiments of the present invention are described by way of illustration only. It is needless to say that the person skilled in the art realizes that the described embodiments may be modified in various different ways without departing from the spirit and scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive in scope.
As shown in fig. 1 to 7, the hydraulic engine braking system comprises a supporting frame 1, the supporting frame 1 comprises a rocker arm mechanism, a moving part or a fixed part, a braking control device 2 and a braking piston device 3 are installed on the supporting frame 1, the braking control device 2 comprises a sealing piston 21 which is slidably installed in the supporting frame 1, a check valve assembly 22 and a pressure limiting valve assembly 23 are respectively communicated with two sides of the sealing piston 21 in the supporting frame 1, a sealing piston reset device is arranged between the sealing piston 21 and the pressure limiting valve assembly 23, a braking start oil duct 24 is communicated between the check valve assembly 22 and the sealing piston 21, a braking oil filling oil duct 25 is communicated between the check valve assembly 22 and the braking piston device 3, a release pressure relief 26 is communicated between the braking piston device 3 and the pressure limiting valve assembly 23, and the sealing piston 21 reciprocates in the supporting frame 1 to cut off the release pressure relief 26.
Referring to fig. 2 and 5, two sides of the sealing piston 21 are respectively provided with a piston starting cavity 27 and a piston oil storage cavity 28, the piston starting cavity 27 is communicated with the one-way valve assembly 22, and the piston oil storage cavity 28 is communicated with the pressure limiting valve assembly 23; the brake actuating oil passage 24 is communicated with the check valve assembly 22 and the sealing piston 21 through the piston actuating cavity 27, the release relief oil passage 26 is communicated between a brake cavity 32 of the brake piston device 3 and the piston oil storage cavity 28, and the sealing piston 21 reciprocates in the piston actuating cavity 27 to communicate and cut off the release relief oil passage 26.
Referring to fig. 2 and 5, the check valve assembly 22 includes a check ball valve 221 for connecting and disconnecting the piston actuating chamber 27 and the brake oil charge passage 25, a check valve return spring 222 is disposed at the top end of the check ball valve 221, and the check valve return spring 222 is connected to the support frame 1 through a check valve plug 223. The check valve assembly 22 has a one-way flow effect so that the brake oil in the piston actuating chamber 27 can enter the brake oil charge passage 25, but the brake oil in the brake oil charge passage 25 cannot flow back to the piston actuating chamber 27.
Referring to fig. 2 and 5, the pressure limiting valve assembly 23 includes a pressure limiting valve body 231 fixedly installed on the support frame 1, a pressure limiting ball valve 232 for pressure relief and pressure maintaining is installed on the pressure limiting valve body 231, a pressure limiting return spring 233 for controlling the pressure limiting ball valve 232 to open and close is arranged at the bottom end of the pressure limiting ball valve 232, a pressure relief hole 234 is arranged on the pressure limiting valve body 231, when the pressure limiting ball valve 232 is opened, the piston oil storage cavity 28 is communicated with the pressure relief hole 234, and brake oil in the piston oil storage cavity 28 can be discharged through the pressure relief hole 234. The designer selects the pressure limiting return spring 233 according to the actual use requirement, and is used for controlling the closing pressure of the pressure limiting ball valve 232, namely, for controlling the pressure which can be reached in the piston oil storage cavity 28 when the pressure limiting ball valve 232 is closed, so as to ensure that when the pressure limiting ball valve 232 is closed, a part of brake oil is stored in the piston oil storage cavity 28, but the movement of the sealing piston 21 at the beginning of the next brake is not influenced.
Referring to fig. 2 and 5, the seal piston return means includes a seal piston return spring 29 connected between the seal piston 21 and the pressure limiting valve assembly 23.
The brake control device 2 operates on the principle that:
when not braking: the brake-starting oil passage 24 has no engine oil pressure, at this time, the sealing piston 21 is kept at the top dead center under the action of the sealing piston return spring 29, the one-way ball valve 221 and the pressure limiting ball valve 232 are both in a closed state, and the release pressure relief oil passage 26 between the brake piston device 3 and the piston oil storage chamber 28 is communicated, and the state is shown in fig. 2.
When braking, the following steps: engine oil enters the piston starting cavity 27 through the brake starting oil duct 24 on the supporting frame 1, simultaneously acts on the one-way ball valve 221 and the sealing piston 21, and pushes the one-way ball valve 221 to be opened against the spring force of the one-way valve return spring 222, as shown in fig. 3, lubricating oil or brake oil enters the brake piston device 3 through the brake oil filling oil duct 25, so that the brake piston is fully extended to realize the maximum stroke of the brake piston, and simultaneously overcomes the pretightening force of the sealing piston return spring 29, thereby pushing the sealing piston 21 to move to the upper end surface of the pressure limiting valve assembly 23, cutting off the release pressure relief oil duct 26 between the brake piston device 3 and the piston oil storage cavity 28 and sealing the release pressure relief oil duct 26; when the brake oil introduced into the brake piston device 3 is filled, the sum of the pressure in the brake oil charge passage 25 and the spring force of the check valve return spring 222 is greater than the pressure in the piston start chamber 27, so that the check ball valve 221 is sealed in a return manner, and high pressure is formed when the brake piston is subjected to the reaction force of the valve by the brake oil charge passage 25, the relief pressure oil passage 26 and the brake piston device 3 due to the incompressible property of the liquid.
When the braking is stopped: when braking is not needed any more, the brake starting oil duct 24 which is led into the piston starting cavity 27 is disconnected, so that the pressure pushing the sealing piston 21 disappears, the sealing piston 21 returns under the action of the sealing piston return spring 29, then the release pressure relief oil duct 26 is communicated with the piston oil storage cavity 28, engine oil is pressed into the piston oil storage cavity 28 through the release pressure relief oil duct 26, when the oil pressure is larger than the spring force of the pressure limiting return spring 233, the brake oil pushes away the pressure limiting ball valve 232 to be discharged through the pressure relief hole 234, the brake piston of the brake piston device 3 begins to return, and the brake piston return is completed. When the pressure of the piston oil storage cavity 28 and the spring force of the pressure limiting return spring 233 reach balance, the pressure limiting ball valve 232 is closed, a part of brake oil is remained in the piston oil outlet cavity and is not completely discharged, when the next braking process is carried out, the whole system is not required to add more brake oil, only a small amount of brake oil is required to be added, the brake piston of the piston braking device can realize braking, the brake oil remained in the piston oil storage cavity 28 can be convenient for realizing quick oil filling in the next braking process, and the state when the seal piston 21 is depressurized is shown in fig. 2. The pressure when the brake oil is released can be controlled by adjusting the oil release pressure of the pressure limiting valve assembly 23, so that the brake oil is prevented from being completely released to cause the overlong oil filling time in the next braking; and the storage of the brake oil is realized through the action of the pressure limiting valve assembly 23, so that the brake oil way can be assisted to be filled more rapidly in the next braking, and the brake oil way has the advantages of stable oil filling, high response speed, high brake sensitivity and the like.
Referring to fig. 3, 4, 6 and 7, the brake piston device 3 includes a brake piston 31 vertically slidably mounted in the support frame 1, and when the brake piston 31 extends, the brake piston drives a brake pin 4 to open a brake exhaust valve 5, the bottom end of the brake piston 31 extends out of the support frame 1 to contact with the brake pin 4, a brake cavity 32 communicating with the brake oil charge oil duct 25 and the release pressure relief oil duct 26 is provided at the top of the brake piston 31, and a brake piston return device 33 is provided between the lower portion of the brake piston 31 and the support frame 1.
Referring to fig. 3, 4, 6 and 7, the top end of the supporting frame 1 is provided with a threaded hole, an adjusting bolt 34 is installed in the threaded hole in a threaded way, the bottom end of the adjusting bolt 34 is installed in the brake cavity 32, the brake cavity 32 limits the bottom end of the adjusting bolt 34 to the brake cavity 32, so that the brake piston 31 cannot be separated from the bottom end of the adjusting bolt 34 when the brake piston 31 moves up and down; the sliding outer circumferential surface of the brake piston 31 matched with the support frame 1 is provided with an antifriction device.
Referring to fig. 3, 4, 6 and 7, the friction reducing means includes a plurality of annular grooves 35 provided on the sliding outer peripheral surface of the brake piston 31. In this embodiment, two annular grooves 35 are provided on the movable outer circumferential surface of the brake piston 31, the annular grooves 35 have the functions of storing oil and containing impurities carried in engine oil, and hydraulic oil is stored in the annular grooves 35 during the up-and-down movement of the brake piston 31, so that the movement friction between the brake piston 31 and the support frame 1 is reduced, when impurities exist, the impurities are limited in the annular grooves 35, the movement abrasion between the brake piston 31 and the support frame 1 is avoided, the clamping stagnation phenomenon occurs, the service life of the brake piston 31 is prolonged, and the braking reliability is improved.
Referring to fig. 3, 4, 6 and 7, a piston sliding portion 311 is provided at an upper portion of the brake piston 31 to be slidably fitted with the support frame 1, and the annular groove 35 is provided at a sliding outer circumferential surface of the piston sliding portion 311 to reduce moving wear between the piston sliding portion 311 and the support frame 1; a piston limit cover 312 surrounding the brake cavity 32 is mounted at the top end of the piston sliding portion 311, a piston oil inlet channel 313 communicating the brake cavity 32 with the brake oil filling channel 25 is arranged on the piston limit cover 312, engine oil from the brake oil filling channel 25 can smoothly enter the brake cavity 32 through arranging the piston oil inlet channel 313, a piston rod 314 extending out of the support frame 1 is arranged at the lower end of the brake piston 31, and the bottom end of the piston rod 314 is in contact with the brake pin 4.
Referring to fig. 3, 4, 6 and 7, the brake piston resetting device 33 includes a return spring baffle 331 mounted at the bottom of the support frame 1, a brake return spring 332 for driving the brake piston 31 to reset is mounted between the return spring baffle 331 and the brake piston 31, and the brake return spring 332 is sleeved outside the piston rod 314, and two ends of the brake return spring 332 respectively abut against the return spring baffle 331 and the piston sliding portion 311. When braking, the hydraulic oil from the brake oil filling duct 25 enters the brake cavity 32, the oil pressure in the brake cavity 32 becomes large, the brake piston 31 is pushed to move downwards against the spring force of the brake return spring 332, when braking is finished, the hydraulic oil is discharged from the release relief duct 26, the oil pressure in the brake cavity 32 is reduced, and the brake return spring 332 pushes the brake piston 31 to move upwards for return; in this embodiment, the brake return spring 332 is sleeved at the outer end of the piston rod 314, is not in contact with the support frame 1, is not connected with the brake cavity 32, hydraulic oil in the brake cavity 32 is not in contact with the brake return spring 332, the working environment of the brake return spring 332 is better, the service life of the brake return spring 332 can be effectively ensured, and compared with the prior art, the brake return spring 332 has better return effect and better braking effect.
Referring to fig. 3, 4, 6 and 7, the upper portion of the adjusting bolt 34 is fixed on the supporting frame 1 by a locking nut 341, a bolt adjusting groove 342 which is beneficial to screwing in and unscrewing out is provided at the top end of the adjusting bolt 34, a limit boss 343 installed in the brake cavity 32 is provided at the bottom end of the adjusting bolt 34, the outer diameter of the limit boss 343 is smaller than the inner diameter of the brake cavity 32, that is, the bottom end area of the brake cavity 32 is larger than the bottom end area of the limit boss 343, a gap L1 is left between the two, so that engine oil entering into the brake cavity 32 can be ensured to directly contact with the bottom end of the brake cavity 32, thereby pushing the brake piston 31 to move downwards more easily, and improving the operation sensitivity of the brake piston 31.
Referring to fig. 3, 4, 6 and 7, a limiting hole 344 for limiting the limiting boss 343 in the brake cavity 32 is provided at the top end of the piston limiting cover 312, the limiting hole 344 is a circular hole or a long hole, in this embodiment, the limiting hole 344 is a circular hole, the inner diameter of the limiting hole 344 is larger than the outer diameter of the adjusting bolt 34 and smaller than the outer diameter of the limiting boss 343, the inner diameter of the limiting hole 344 is larger than the outer diameter of the adjusting bolt 34, so that when the piston limiting cover 312 can move up and down along the adjusting bolt 34, a gap is provided between the outer diameter of the adjusting bolt 34 and the inner diameter of the limiting hole 344, so that hydraulic oil can enter the brake cavity 32, and the gap between the outer diameter of the adjusting bolt 34 and the inner diameter of the limiting hole 344 is the piston oil inlet channel 313; the outer diameter of the limit boss 343 is larger than the inner diameter of the limit hole 344 to ensure that the limit boss 343 is restricted in the brake cavity 32 to ensure that the maximum stroke of the brake piston 31 is always S. When the lower bottom surface of the limit boss 343 is in contact with the bottom surface of the brake cavity 32, the maximum gap between the lower bottom surface of the piston limit cap 312 and the upper top surface of the limit boss 343 is the maximum brake stroke S of the brake piston 31 or the brake piston device 3, and when the brake stroke is 0, the lower bottom surface of the piston limit cap 312 is in contact with the upper top surface of the brake piston 31. The maximum gap between the lower bottom surface of the piston limit cap 312 and the upper top surface of the limit boss 343 is the maximum braking stroke S of the present invention, which is stable and reliable, and is convenient for manual direct measurement, reducing the measurement difficulty and improving the measurement efficiency.
The top end of the adjusting bolt 34 is provided with a bolt adjusting groove 342 which is beneficial to screwing in and out, and the bolt adjusting groove 342 can be convenient for the rotation adjustment of tools such as screwdrivers or screwdrivers.
The working principle of the brake piston device 3 is as follows:
when not braking: when the brake control device 2 is not in operation, no engine oil pressure exists in the brake oil charge channel 25, the cold brake valve clearance L of the engine is adjusted by rotating the adjusting bolt 34, and under the action of the return spring baffle 331 and the brake return spring 332, the bottom surface of the brake cavity 32 is tightly attached to the lower bottom surface of the limit boss 343, see fig. 3 and 4.
When the brake is started: engine oil enters the brake oil charge channel 25 through the brake control device 2, then enters the brake cavity 32 through the piston oil inlet channel 313 on the piston limit cover 312, oil pressure is generated in the brake cavity 32, the brake piston 31 is pushed to move downwards against the spring force of the brake return spring 332, and when the upper top surface of the limit boss 343 is contacted with the lower bottom surface of the piston limit cover 312, the brake piston 31 is completely extended, so that the maximum stroke S of the brake piston 31 is realized. The brake piston 31 is extended to contact with the brake pin 4, engine oil in the brake cavity 32 is compressed into high-pressure oil under the reaction force of the brake exhaust valve 5 and the action of the brake control device 2, and the brake exhaust valve 5 is opened in combination with the brake stroke of the brake piston 31 or the brake lift of the cam to realize engine braking, and the extended state of the brake piston 31 is shown in fig. 6 and 7.
At the end of braking: when braking is no longer needed, the brake oil is discharged from the release pressure relief oil duct 26, so that the pressure pushing the brake piston 31 disappears, the brake piston 31 is reset under the action of the brake return spring 332, the lower bottom surface of the piston limit cover 312 is not contacted with the upper top surface of the limit boss 343, and under the action of the brake return spring 332, the bottom surface of the brake cavity 32 is contacted with the lower bottom surface of the limit boss 343, see fig. 3 and 4.
Valve clearance adjustment principle: when the valve clearance needs to be adjusted, the adjusting bolt 34 is screwed downwards, the adjusting bolt 34 drives the limiting boss 343 to move downwards, then pushes the brake piston 31 to move downwards, at this time, the maximum brake stroke between the limiting boss 343 and the brake cavity 32 is unchanged and still is S, but the valve clearance between the brake piston 31 and the brake pin 4 is reduced, the valve clearance adjustment range is L in fig. 3, and when the brake piston 31 moves downwards gradually, the valve clearance L is reduced gradually.
The foregoing has shown and described the basic principles, main features and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (7)
1. The hydraulic engine braking system comprises a supporting frame, wherein a braking control device and a braking piston device are installed on the supporting frame, and the hydraulic engine braking system is characterized in that: the brake control device comprises a sealing piston arranged in a supporting frame, a one-way valve assembly and a pressure limiting valve assembly are respectively communicated with two sides of the sealing piston in the supporting frame, a sealing piston resetting device is arranged between the sealing piston and the pressure limiting valve assembly, a brake starting oil duct is communicated between the one-way valve assembly and the sealing piston, a brake oil filling oil duct is communicated between the one-way valve assembly and the brake piston device, a release pressure relief oil duct is communicated between the brake piston device and the pressure limiting valve assembly, and the sealing piston reciprocates in the supporting frame to be communicated with and cut off the release pressure relief oil duct;
the brake piston device comprises a brake piston vertically and slidably arranged in the support frame, the bottom end of the brake piston extends out of the support frame to be in contact with a brake pin, a brake cavity communicated with the brake oil charge oil duct and the release pressure relief oil duct is formed in the top of the brake piston, and a brake piston resetting device is arranged between the lower part of the brake piston and the support frame;
the pressure limiting valve assembly comprises a pressure limiting valve body fixedly arranged on the supporting frame, a pressure limiting ball valve for pressure relief and pressure maintaining is arranged on the pressure limiting valve body, a pressure limiting return spring for controlling the pressure limiting ball valve to open and close is arranged at the bottom end of the pressure limiting ball valve, and a pressure relief hole is formed in the pressure limiting valve body;
an adjusting bolt is arranged at the top end of the supporting frame in a threaded manner, and the bottom end of the adjusting bolt is arranged in the brake cavity; an antifriction device is arranged on the sliding peripheral surface of the brake piston matched with the support frame;
the upper part of the brake piston is provided with a piston sliding part which is in sliding fit with the support frame, and the lower end of the brake piston is provided with a piston rod which extends out of the support frame; the brake piston resetting device comprises a return spring baffle plate arranged at the bottom of the supporting frame, a brake return spring for driving the brake piston to reset is arranged between the return spring baffle plate and the brake piston, the brake return spring is sleeved outside the piston rod, and two ends of the brake return spring are respectively propped against the return spring baffle plate and the piston sliding part.
2. The hydraulic engine braking system of claim 1 wherein: the two sides of the sealing piston are respectively provided with a piston starting cavity and a piston oil storage cavity, the piston starting cavity is communicated with the one-way valve assembly, and the piston oil storage cavity is communicated with the pressure limiting valve assembly; the brake starting oil duct is communicated with the check valve assembly and the sealing piston through the piston starting cavity, the release pressure relief oil duct is communicated between the brake cavity and the piston oil storage cavity, and the sealing piston is communicated in the piston starting cavity in a reciprocating mode and cuts off the release pressure relief oil duct.
3. The hydraulic engine braking system of claim 2 wherein: the one-way valve assembly comprises a one-way ball valve which is used for connecting and disconnecting the piston starting cavity with the brake oil filling oil duct, a one-way valve return spring is arranged at the top end of the one-way ball valve, and the one-way valve return spring is connected to the supporting frame through a one-way valve plug.
4. The hydraulic engine braking system of claim 1 wherein: the seal piston return device comprises a seal piston return spring connected between the seal piston and the pressure limiting valve assembly.
5. The hydraulic engine braking system of claim 1 wherein: the friction reducing means includes a plurality of annular grooves provided on a sliding outer peripheral surface of the brake piston.
6. The hydraulic engine braking system of claim 1 wherein: the top end of the piston sliding part is provided with a piston limiting cover which surrounds the brake cavity, and the piston limiting cover is provided with a piston oil inlet channel which communicates the brake cavity with the brake oil filling oil duct.
7. The hydraulic engine braking system of claim 6 wherein: the upper part of the adjusting bolt is fixed on the supporting frame through a locking nut, a bolt adjusting groove which is beneficial to screwing in and screwing out is formed in the top end of the adjusting bolt, a limiting boss which is arranged in the brake cavity is formed in the bottom end of the adjusting bolt, and the outer diameter of the limiting boss is smaller than the inner diameter of the brake cavity; the top end of the piston limiting cover is provided with a limiting hole which limits the limiting boss in the brake cavity, and the limiting hole is a round hole or a long hole.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910939444.4A CN110578571B (en) | 2019-09-30 | 2019-09-30 | Hydraulic engine brake system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910939444.4A CN110578571B (en) | 2019-09-30 | 2019-09-30 | Hydraulic engine brake system |
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| CN110578571A CN110578571A (en) | 2019-12-17 |
| CN110578571B true CN110578571B (en) | 2024-03-08 |
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| CN201910939444.4A Active CN110578571B (en) | 2019-09-30 | 2019-09-30 | Hydraulic engine brake system |
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| CN201159104Y (en) * | 2007-12-29 | 2008-12-03 | 侯训波 | Hydraulic brake of engine |
| CN101649761A (en) * | 2009-08-16 | 2010-02-17 | 李金龙 | Gas bleed brake of engine |
| CN202510226U (en) * | 2012-04-01 | 2012-10-31 | 深圳市特尔佳科技股份有限公司 | Engine brake |
| CN102828837A (en) * | 2012-09-10 | 2012-12-19 | 浙江亿日气动科技有限公司 | Frame-type air-valve executing device driven by assistant cam |
| CN109184847A (en) * | 2018-08-27 | 2019-01-11 | 南京威孚金宁有限公司 | A kind of engine compresses release braking valve control system and its working method |
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2019
- 2019-09-30 CN CN201910939444.4A patent/CN110578571B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201159104Y (en) * | 2007-12-29 | 2008-12-03 | 侯训波 | Hydraulic brake of engine |
| CN101649761A (en) * | 2009-08-16 | 2010-02-17 | 李金龙 | Gas bleed brake of engine |
| CN202510226U (en) * | 2012-04-01 | 2012-10-31 | 深圳市特尔佳科技股份有限公司 | Engine brake |
| CN102828837A (en) * | 2012-09-10 | 2012-12-19 | 浙江亿日气动科技有限公司 | Frame-type air-valve executing device driven by assistant cam |
| CN109184847A (en) * | 2018-08-27 | 2019-01-11 | 南京威孚金宁有限公司 | A kind of engine compresses release braking valve control system and its working method |
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